Slice off the very top of the garlic head. Drizzle with olive oil and season with salt and pepper. Place a on baking sheet and roast for 35 minutes. Remove from oven and let cool. Remove the cloves and mash with a wooden spoon.

Place potatoes in a large pot and cover with cold water. Add salt and bring to a boil. Cook until fork tender and drain. Using a handheld mixer, cream potatoes until smooth.